Symptom Related Diagnostic Procedures

CIRCUIT DESCRIPTION
This engine is equipped with a distributor-less ignition system called the Electronic Ignition (EI) system. The primary circuit of the EI system consists of 2 separate ignition coils, an electronic Ignition Control Module (ICM) and a Crankshaft Position (CKP) 1 sensor as well as the related connecting wires and the Ignition Control (IC) portion of the Powertrain Control Module (PCM). Each secondary circuit consists of the secondary winding of the coil, spark plug wires, and the spark plugs.

IMPORTANT: The Camshaft Position (CMP) sensor is only used for a misfire detection and is not part of the ignition system.

DIAGNOSTIC AIDS
Test/Inspect for the following conditions:
^ Collapsed air intake duct.
^ Restricted air filter element. Refer to Air Cleaner Element Replacement.
^ A TP sensor that reads too high or skewed may cause an incorrect fueling condition.
^ A Throttle Position (TP) sensor binding or sticking in wide open position.
^ A TP sensor shorted or open.
^ Fuel contamination
^ Out of fuel
^ Restricted exhaust system. Refer to Restricted Exhaust in Exhaust System. Testing and Inspection
^ Low compression - refer to Engine Compression Test in Engine Mechanical.
^ A cold engine that has not been started should display Engine Coolant Temperature (ECT) and Intake Air Temperature (IAT) temperatures that are relatively close to each other.
^ A skewed Manifold Absolute Pressure (MAP) sensor. The MAP sensor value should change when cranking the engine. Compare any questionable barometer readings with that of a known good vehicle.

Check for intermittent conditions. Refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-10:

The number below refers to the step number on the diagnostic table.
3. While cranking the engine, the Crankshaft Position (CKP) activity (CKP reference signal) should increment to 255, then rollover to 0.